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New To Ziva! Have a couple of questions...

ElliotS

Hi! My name is Elliot and I am looking into Ziva as a modeling tool for a company I do design/figurative/R&D work for. We have our standard figure models (and occasionally new models that we generate) that we commonly have to re-pose and 3D Print for various clients. We have very limited rigging/skinning expertise in-house, and Ziva seems like a perfect tool to circumvent this lack and leverage our other skill sets. As it stands now, we take an approved model, rig and skin it in a base-level manner in Maya (we are NOT a VFX house nor do we do any animation, so what is a 'good' rig to us is undoubtedly very rudimentary to most of the folks on this forum), pose it, and very often spend quite a bit of time fixing in ZBrush what our Maya rigs break before prepping for print. This 'fixing' stage can be time consuming for us, and not all our digital artists have the anatomy background to correct the rigging artifacts from the more extreme poses. It is my hope that Ziva can help us re-shape this workflow.

I'd like to lay out a couple of high-level questions I have about how to use Ziva for this purpose. I feel comfortable that
we can do most of the required work to get Ziva operating, but there are gaps in my understanding, and I want to be sure that we will be able to handle the requirements in those gaps (either with our current skill sets, or determine what we need to learn to fill the gaps); to do that, I feel I need to outline what (I think) I understand about how it works to point out the areas I am fuzzy on (these steps are only approximately in order):

1) We want to go from this (standard 'A' or 'T' pose) to this (some arbitrary pose) After animating the bones (the method is really not important), those bones with their animations are exported to an Alembic file, which is imported into Maya and assigned Ziva Bone object status:

2) To do this with Ziva, we build a model of a skeleton inside the approved model, then build muscle objects in the same fashion:

3) Using the Ziva commands, muscles are attached (loosely or firmly) to bones:

4) By painting the 'start' and 'end' of muscle objects, the fiber direction of a muscle can be established, so that, when the Line of Action changes length (by being riveted to adjacent bone objects), the muscle can 'flex' and firm up axially:

5) A fascia object is made by 'shrink wrapping' (possibly using Ziva simulation to do this by making it a Ziva Cloth object and applying one or more forces) a figure model around the bones and muscles in the base pose ('A', 'T', or other):

...this is where things start to get murky for me...

6) In reading/watching all the material I have viewed (not all that is available, certainly, but much of it), I see this
kind of scenario used:

7) But, not understanding how the final 'hero model' is made (which is where all of this is going), I would assume that
something like this would be eventually required, since the models will have heads, hands, and feet:

8) But continuing on with what I have seen so far, a copy of this fascia object is Wrapped (we already use Wrap 3 in our pipeline) to the original approved model, and a skin/fat 'glove' is made by bridging the open ends of the skin/fat object to the corresponding open ends of yet another copy of the fascia object; this makes a watertight, non-zero-volumed object that the Ziva tet mesh can populate volumetrically:

9) The muscles are Ziva simmed over the Alembic cache of the bones being animated (Lines of Action, where applicable), and are Alembic cached themselves, becoming the 'bones' for the fascia in the next step:

10) If I understand correctly, since in Ziva 1.4 fascia and fat/skin can be simmed simultaneously, the fat/skin glove we
made is now assigned Tissue status and simmed over the animated muscle and bone geometry that had been Alembic cached and is now the Ziva Bone Objects:

It is at this point I lose the thread of what to do next in two respects (again, we are not VFX folks, so if any of this is
common knowledge in that part of the industry, please forgive our ignorance and could you point us in the direction of the skills/tools/knowledge required to complete these steps?):

11) All the tutorials seem to use relatively low-poly models. I understand that this may be just for purposes of performance while conducting webinars and such, but are we eventually driving a high-poly 'hero' model with a low-poly model to get the final result? If so, I am unclear how that is done:

12) Also, are heads/hands/feet to be simmed separately? If so, how are they attached later into a final hero model? If not, how is the fascia attached to the skin/fat if there is no bridge? is the Fascia just
an Alembic-baked 'bone' driving the skin/fat object but otherwise not geometrically connected?:

13) On the subject of resolution, how are effects like the 'rhino skin' accomplished over a whole character if a fairly
high-poly model isn't directly simulated in Ziva? Am I underestimating the density of final mesh Ziva will happily handle?:

Now, if some of this is covered somewhere that I missed, please send me that way; I'm not looking to have anyone teach me a whole discipline. Also, if simply downloading the trial and opening the demo files will answer these questions, just say so.

Thank you for your time! I look forward to all the possibilities with Ziva! Cheers, Elliot

Essex

These illustrations are fantastic and I love them!

ElliotS

Hey thanks, Essex!

jamesj

ElliotS I wholeheartedly agree with Essex's sentiment - really great illustrations 😀
They really present the process in a super friendly and approachable manner.

It's also super gratifying to see that the process, with its basis in anatomy and phics, was clear to you even though you don't have significant prior experience with character rigging.
Ironically, the parts that are still unclear, are those that use more typical rigging approaches.

To answer your questions . . .
Correct me if I missed something, but I think that your questions boil down to "How do I attach the head, hands and feet?" and "Can Ziva simulate high resolution meshes?"

I'll answer those below:

**

How do you attached the head, hands and feet back onto your hero model?

**

Have three copies of the model with the head, hands and feet attached.

Either use Ziva's embedder Ziva->Embedded Mesh or Maya's wrap deformer and deform the first of the intact meshes with the ziva simulated mesh.

With the joint hierarchy you used to pose the ziva bones, apply a basic skinCluster to the second intact mesh - you should only need to worry about the quality of the results on the head, hands and feet.

Select the second mesh and then the third mesh and add a blendShape deformer (make sure that Origin is set to "local" and Deformation Order is set to "After") - set the blend weight to 1.0

Select the first mesh and then the third mesh and add a blendShape deformer (use the same settings) - and set the blend weight to 1.0

Right click on the third mesh and drop down to the paint option and paint the weights for the 2nd blendShape deformer.

Using the paint context tool, reveal the deformations of the head, hands and feet by painting the blend weight to a value of 0.0 (like a mask in photoshop)

If done properly, the head, hands and feet should now be deformed with your skinCluster and the rest of the character should be deformed with the result of the ziva simulation.

(Alternatively, you can deform the entire character with Ziva VFX directly if you like - there is no requirement that you remove the head, hands and feet)

**

All the tutorials seem to use relatively low-poly models. I understand that this may be just for purposes of performance while conducting webinars and such, but are we eventually driving a high-poly 'hero' model with a low-poly model to get the final result? If so, I am unclear how that is done.

**
You can deform high resolution models with Ziva. We decouple the resolution of out tetrahedral meshes from the final deforming mesh anyway. Alternatively, you can rig with a lower resolution mesh (so it is easier to paint attachments, materials and whatnot) and then by using the Embedder, add your high resolution mesh so that it can be driven by the same tetrahedral mesh. (or use a Maya wrap)

Let me know if you require any further clarification - and feel free to illustrate these steps if you like 🙂

-jj

tristan_cordeboeuf

Same for me ! I'm impressed by the illustration!!

ElliotS

tristan_cordeboeuf , thanks, man! They were fun to draw! I think I'll name the skeleton Ivan.jamesj Thank you, James, this is exactly what we were looking for! Yes, those are, essentially, my burning questions. Mostly just needed a nudge in the right direction to make sure we weren't biting off more than we can chew, and with the outlines you provided I feel warm and fuzzy about moving forward. We will start the process of DLing the trial and getting started so we can vet Ziva for our pipeline and justify the expense to the higher-ups.

As for understanding the process: I absolutely got the gist of Ziva right away! I personally think it is quite straight forward (apart from my more in-the-weeds questions, of course). I'm not even a Maya user (that is the weapon of choice of my partners-in-crime; I'm learning, but I use Max at the moment), but I was delighted to find that, at least to me, the Ziva method of moving a character was far more obvious than all the (to me) counter-intuitive rigging/skinning options out there; I'm very excited by the prospect of being able to leverage my anatomy training here for more than just corrections!

And Ivan may well make another appearance if I get stuck 😀

Cheers,
Elliot

Michael

Hi Elliot, really enjoyed reading your breakdown of the Ziva workflow. With your permission, we'd love to share this further than this forum post (on website, social, etc.). Are you okay with that? I work with a lot of our studio users and partners and your visuals really get to the fundamentals of our tech! And, let us know how we can help your team's continued exploration.

ElliotS

Hi Michael, please do! We're delighted that you all have enjoyed this 'roadmap' of our understanding of Ziva, and if that helps you communicate with others, all the better! And thank you, we will be getting our trial version set up soon (gotta clear our schedule, which is always a moving target), and I'm sure we will be asking for help and/or guidance now and again over the next couple of weeks 🙂 Cheers! Elliot

Oh, and if some or all of this shows up in some public place (on your website, for example), would you mind letting us know? Wanna collect on our 15 minutes of fame... 🙂